If the man is unable to breathe under water and survive without oxygen, some fish can. This is just demonstrated by a study by British and Norwegian scientists.
Fish produce alcohol
Carassians Carassius carassius and goldfish Carassius auratus living in northern Europe and Asia have learned to survive under the ice. For five or six months, they can not rise to the surface, their cells then produce alcohol by transforming lactic acid waste that forms in cells deprived of oxygen into ethanol the most abundant alcohol and the most known. Those fishes reject it by their gills. Thanks to this process, fish do not accumulate lactic acid in the muscles and therefore do not stock it. And that’s how they manage to survive for several months without breathing, well done! But in these extreme conditions, they are forced to save their energy, they “reduce or even stop some processes that consume energy, such as vision,” says Cathrine Fagernes, co-author of the study. When they use this method, the alcohol level in their blood is pretty impressive, about 0.5 g per liter! Fortunately they do not drive!